body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
    "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
    sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

code {
  font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New",
    monospace;
}

* {
  box-sizing: border-box;
}

.calculator {
  display: grid;
  grid-template-columns: repeat(4, 6rem);
  grid-template-rows: minmax(6rem, auto) repeat(5, 4rem);
  gap: 1px;
  background-color: #F0F3F9;
  width: calc(24rem + 3px);
  margin: auto;
}

.output {
  grid-column: 1 / span 4;
  /* border: 2px solid lightgray; */
  display: flex;
  flex-direction: column; /*竖轴为主轴*/
  align-items: flex-end; /*向右对齐*/
  justify-content: space-around; /*在每行上均匀分配弹性元素*/
  padding: 10px;
  /*让输入/输出的数如果超过长度就打断放到下一行：*/
  word-wrap: break-word;
  word-break: break-all;
}

.last-ouput {
}

.cur-output {
  font-size: 3rem;
}

.calculator>button {
  background-color: #FFFFFF;
  border-radius: 5%;
  border: solid #E2E5EA;

}

.calculator>button:hover {
  background-color: #FBFCFD;
}


